package string;

/**
 *
 */
public class StringBuilderDemo {
    public static void main(String[] args) {
        String str = "好好学习java";
        StringBuilder builder = new StringBuilder(str);


        //append():追加内容----在末尾追加加
        builder.append(",为了找个好工作");
        System.out.println(builder);


        //replace():替换部分内容（含头不含尾）
        builder.replace(9,16,"就是为了改变世界");
        System.out.println(builder);


        //delete():删除部分内容（含头不含尾）
        builder.delete(0,8);//删除下标为0到7的
        System.out.println(builder);



        //insert():插入内容
        builder.insert(0,"活着");//在下标0的位置插入活着
        System.out.println(builder);


        //reverse():反转
        builder.reverse();//反转builder的内容
        System.out.println(builder);


        StringBuilder builder1 = new StringBuilder("a");
        for (int i = 0;i<100000000;i++){
            builder1.append("a");
        }
        System.out.println("执行完毕");












































































        //StringBuilder的创建方式:
        /*
        StringBuilder builder1 = new StringBuilder();//空字符串
        StringBuilder builder2 = new StringBuilder("abc");//abc串
        */

        //String和StringBuilder互转：
        /*
        String str = "abc";
        StringBuilder builder3 = new StringBuilder(str);//abc串，基于String对象构造StringB
        String str2 = builder3.toString();//将builder3转换为String
         */
















    }
}
